1. Field of the Invention
The present invention relates to an apparatus for a negative carrier for a photographic printer for positioning a negative film when an image on the negative film is printed on a photosensitive material, and is applicable to, for instance, a printer processor in which a photographic printer and a processor are combined.
2. Description of the Related Art
A printer processor, which is popularly known as a mini lab, is installed in a DPE shop (the "DPE shop" refers to a shop where photographic films are commercially processed) or the like. A printer section for print-exposing an image recorded on a negative film onto photographic printing paper and a processor section for processing the printing paper subjected to print-exposure are integrated in the printer processor. By simply setting the elongated printing paper in the printer processor, the printer processor is capable of automatically transporting and processing the printing paper in the printer section and the processor section. In the printer section of the printer processor, the image on the negative film is printed onto the printing paper after being enlarged to a selected fixed size, and the printing paper with images printed thereon is consecutively transported to the processor section where it is developed and finished as a photographic print.
When the image on the negative film is exposed and printed onto the printing paper, from the viewpoint of the operating efficiency the negative film is conventionally subjected to print-exposure while being automatically transported in a negative carrier for positioning the negative film on a worktable of the printer processor.
For this reason, when the negative film is subjected to exposure processing while the negative film is being transported in the negative carrier, it is necessary to provide in the negative carrier sensors for detecting the presence of the negative film in the negative carrier, the presence of an image frame on the negative film, and other information concerning the image frame, such as sensors for detecting a leading end, perforations, a spliced portion, an image plane, a frame number code (FNC), and a DX code. Each of such sensors is comprised of a light-emitting element, such as an LED, and a light-receiving element for receiving light from the light-emitting element. However, since the amount of light emitted from the light-emitting element declines or the sensitivity of the light-receiving element changes over time, it has been necessary to periodically calibrate the sensors for detecting the items of information concerning the negative film.
However, if a means for automatically calibrating the sensors is merely provided, there is a possibility of erroneously calibrating the sensors in a state in which the negative film is located over the sensors, thereby making it impossible to calibrate the sensors properly. Accordingly, since the calibration of the sensors is conventionally carried out by expert personnel for maintaining the negative carrier periodically, there has been a drawback in that the calibration of the sensors is troublesome.